You want to check your own draft before you hand it in. GPTZero is the free academic standard most students and professors already recognise. TextSight is the newer self-check pick: per-sentence highlights on the free tier, a bundled rewriter for fixing the lines that flag, and calibration aimed at not over-flagging non-native English. This is the honest pre-submission comparison, no marketing spin. Free to try, no card.
Both products were built for the same job. The right way to choose between them is to look at what a real pre-Turnitin draft check demands.
Both GPTZero and TextSight scan a piece of writing, return an AI probability, and highlight suspicious sentences. Because they overlap so directly, the comparison comes down to four things students care about: free-tier generosity, how the evidence is shown, how non-native English is handled, and how much the paid tier costs once you outgrow free.
Students rarely plan ahead. The 2am workflow rewards tools that work in one click, no friction, no upsell modal. GPTZero gives more scans a day on free after signup. TextSight gives sentence-level highlights and Plagiarism Risk on free, with no signup required for the first scan and 2 free AI rewriter uses for fixing flagged sentences.
A document-level score without sentence-level highlights is hard to act on. You see the score is 62 but you do not know which sentences are pulling it down. GPTZero free shows a basic colour band. TextSight free shows full sentence-level highlights with a confidence indicator on each one, so you know exactly which sentences to rewrite.
Formal English instruction in Indian, Chinese, Korean, and many European schools teaches the same five-paragraph essay structure that ChatGPT defaults to. Detectors not calibrated for ESL register over-flag these students for essays they wrote themselves. TextSight is explicitly tuned for this. GPTZero is general-purpose and does not advertise ESL calibration.
If you write 2 or 3 essays a month, free tiers from both cover you. If you are in dissertation season or writing weekly, you will outgrow free. GPTZero Premium is around $14.99 a month. TextSight Pro bundles the AI rewriter that GPTZero sells as a separate Origin subscription.
The honest spec sheet for students. Where each one wins, in one scrollable table.
| Feature | TextSight | GPTZero |
|---|---|---|
| Primary product | AI detector with sentence-level evidence and bundled AI rewriter | Academic AI detector with perplexity plus burstiness classifier |
| Detection type | Multi-signal classifier, sentence-level confidence | Perplexity plus burstiness, document-level band |
| Free tier | 3 scans/day, 5,000 chars/scan, sentence highlights, no signup for first scan | ~10 scans/day after signup, 10,000 chars/scan, basic colour band |
| Pricing model | Free, Starter, Pro, Business with monthly or yearly billing | Free and Premium with flat retail pricing |
| Entry price | Starter $9.99/mo monthly, $7.49/mo yearly | Premium $14.99/mo flat |
| Pro annual effective | $14.99/mo (Pro yearly, $179.88/yr) | $14.99/mo (Premium, no yearly discount published) |
| Sentence-level evidence | Per-sentence confidence on free and paid | Document-level read on free, sentence highlights on Premium |
| Non-native English handling | Tuned to read formal ESL prose as Mixed rather than Likely AI more often | General-purpose; no published ESL calibration |
| Model coverage | Retrained against current ChatGPT, Claude, Gemini output | Advertises a broad named-model set, updated as models ship |
| Bundled AI rewriter | Yes, in the same view as the scan, 2 lifetime free uses | No, sold as a separate product |
| Plagiarism read | Plagiarism Risk in the same scan view | Offered as a separate plagiarism product |
| REST API | Yes, on Business at $29.99/mo yearly | Yes, separate API plan |
| Best fit | Students who want sentence evidence and a rewriter in one free self-check | Students whose professor already trusts the GPTZero brand |
Feature and pricing details reflect each tool's public pages. Verify current pricing on the vendor pricing page before committing to a paid plan.
Yearly billing saves 25 percent. Full details on the pricing page.
Billed $89.88/year, save $30
Billed $179.88/year, save $60
Billed $359.88/year, save $120
For comparison, GPTZero Premium is around $14.99 a month.View full pricing →
Honest call-outs. These are real reasons many students stick with GPTZero, especially if they were already using it before TextSight existed.
GPTZero is the AI detector that landed in the New York Times, the BBC, NPR, and pretty much every back-to-school explainer your professor has read. If you tell your instructor you ran your essay through GPTZero and it came back clean, they know what you mean. That credibility matters if you ever end up defending your work in an academic integrity meeting.
The GPTZero extension has been on the Chrome Web Store since 2023 and is genuinely well-built. You can select text inside Google Docs, Notion, or Gmail and scan it in two clicks without leaving the page. TextSight ships a Chrome extension too, but GPTZero's is more polished and has the larger install base.
GPTZero free gives around 10 scans a day at 10,000 characters per scan after a quick signup. TextSight free gives 3 scans a day at 5,000 characters per scan. If you run iterative cycles of paste, score, rewrite, repaste during a long editing session, GPTZero's higher daily allowance lets you go longer before hitting a paywall.
GPTZero advertises explicit coverage of ChatGPT, GPT-4, Claude, Gemini, LLaMA, and a wide set of newer models, with classifier updates published as new models ship. TextSight retrains regularly against current ChatGPT, Claude, and Gemini, but does not advertise the same breadth of named model support.
The perplexity and burstiness approach was published openly by Edward Tian and the GPTZero team during the company's Princeton origin in 2023. You can read the original methodology, cite it in academic work, and defend it on technical grounds. That documentation depth is genuinely useful if you ever need to justify your tool choice in a hearing.
Five specific reasons students migrate from GPTZero to TextSight, or run TextSight first in their cross-check workflow.
When TextSight flags your essay at 62, the colour map shows you exactly which sentences scored worst, with a confidence indicator on each one. You see the evidence behind the score, not just the score itself. GPTZero free shows a basic colour band on the document but does not give you the same per-sentence confidence breakdown. For revising before submission, that evidence depth is the difference between guessing what to fix and knowing.
This is the big one for international and non-native English students. Formal English instruction in Indian, Chinese, Korean, and many European schools teaches the same tidy, low-variance essay structure that AI models default to, which means general-purpose detectors can over-flag students for essays they wrote themselves. TextSight is tuned to read that register as Mixed rather than Likely AI more often, and the per-sentence map shows you which lines drove the score so you can judge each one yourself. GPTZero is general-purpose and does not publish ESL calibration. No detector is reliable enough to settle this on its own, which is why the sentence evidence matters more than the headline number.
The TextSight free tier covers most single-essay pre-submission self-checks at zero cost. Pro is $19.99 a month standard and $14.99 a month on annual billing. For students writing two or three essays a month, free is the right starting point; Pro is the step up for dissertation season and finals weeks when you are scanning constantly.
A flagged paragraph without an action plan is just anxiety. TextSight keeps a rewriter in the same view as the scan, so you can rework a flagged sentence and re-read it without switching tabs. GPTZero has no integrated rewriter; the equivalent is a separate product. The point is to fix the lines that genuinely read as AI, not to game a score on prose you wrote yourself.
Every scan you run on TextSight Pro is kept for 90 days with the highlights intact, so you can show your supervisor or thesis committee exactly what the detector saw before you submitted. GPTZero keeps a scan history too, but it is less prominent in the student-tier UI. For dissertation students and anyone who may need to defend a submission later, the audit trail is worth the price difference on its own.
Use this as a quick decision matrix for the most common student workflows. If your situation is mixed, run both, in the order shown.
Pick TextSight first for its ESL-aware reading and per-sentence evidence, so you can judge each flagged line yourself. Cross-check with GPTZero only if your professor specifically asks.
Try TextSight free →Pick TextSight Pro for unlimited scans, 90-day audit history, full AI rewriter, and sentence-level highlights. Use GPTZero free as a final cross-check.
Get Pro →Free tiers from both, run in sequence, cost nothing. Start with TextSight for sentence-level evidence, finish with GPTZero free for the second-classifier cross-check.
Start free →Pick TextSight Pro for unlimited scans and the bundled AI rewriter. GPTZero Premium is competitive on price but does not include the AI rewriter.
See Pro →If you can only pick one, here is the call. If you can run both, here is the order.
Pick TextSight as your primary self-check: per-sentence evidence on free, an ESL-aware reading that is friendlier to formally-taught prose, a rewriter in the same view for fixing flagged sentences, and scan history on Pro. Best daily driver for students who want the evidence behind the score, not just the score, and who may have written in a register that general-purpose detectors flag too aggressively.
Use GPTZero as the cross-check: independent perplexity plus burstiness algorithm, broader advertised LLM model coverage, mature Chrome extension, brand recognition with professors, higher daily free quota. Run it after TextSight as a second-classifier sanity check. Two independently trained detectors both reading green is meaningfully stronger than either one alone, and that is the workflow students with the lowest flag rates on submission actually run.
One-line answer: for ESL students and anyone who wants sentence-level evidence, TextSight first. For students whose professor already specifically trusts GPTZero, GPTZero first, then TextSight as the second opinion. Either way, run both before submission, because the cost is zero and the upside is catching one extra flagged paragraph before your professor does.
All-audience deep comparison, with feature parity matrix and the cross-check workflow.
See the full vs page →Seven-tool ranking with Turnitin correlation and false-positive rates side by side.
See the ranking →The pre-scan workflow that catches Turnitin flags before your professor does.
Read the guide →The student workflow and the academic tone preset.
See the student hub →Free to try. No card. Sentence-level evidence and ESL-aware scoring.
Honest head-to-heads with other detectors and humanizers.